1. Technical Field
The present invention relates in general to motor vehicle safety systems. More particularly, the present invention relates to an airbag apparatus for motor vehicles. More specifically, but without restriction to the particular embodiment and/or use which is shown and described for purposes of illustration, the present invention relates to an airbag apparatus that includes an impact absorbing mechanism.
2. Discussion
Automobiles have incorporated many safety systems into their design over the years to help protect the occupants during various types of collisions. The seatbelt, which keeps occupants securely fastened to their seat, was and arguably still is the most prevalent safety device in the industry.
In recent years, both the government and the automotive industry realized the advantages that an inflatable occupant restraint system or airbag system could provide. The drive to develop and implement such a system was so strong that within just a few years almost all vehicles included inflatable occupant restraints that protected occupants during frontal collisions. Soon after the introduction of these frontal airbags, the industry began looking for ways and methods of protection during side collisions.
One intuitive response was to incorporate inflatable restraints to enhance the protection of the occupants during a collision from the lateral side of a vehicle. These inflatable restraints for lateral or side collisions have been placed in a number of locations within the vehicle. For example, some vehicles have airbags placed in the side of the vehicle seat whereby during a collision the airbag deploys from the side of the seat and forms against the lateral side of the vehicle interior. Other vehicles have placed airbags in the doors that protect during side collisions. Sometimes, due to packaging constraints, it is preferable to place an airbag in either a pillar or over the door header as disclosed in U.S. Pat. No. 5,791,683 assigned to Toyota Gisei Company Limited. Unfortunately, this leads to a number of problems. Most specifically, vehicle regulations in the United States now require that portions of the vehicle interior above the belt line of the occupants have specific energy absorbing characteristics. This requirement FMVSS 201 has lead automotive companies to place impact countermeasures behind headliners and trim pieces in order to satisfy this energy absorbing requirements. Countermeasures include, but are not limited to, energy absorbing foam and crushable plastic ribs that act to absorb impact energy.
It is obviously desirable to have a clear, appointed path for any airbag. This is typically employed by the use of the deployment door that is hinged on one end and is moved out of the way by the force of the airbag. This is the standard practice for frontal airbags disposed within the steering wheel, the instrument panel of the vehicle, and a vehicle door. This standard practice becomes more difficult when airbags are disposed in a pillar over the door header. The '683 patent includes such an airbag and disclosures a garnished trim that opens to allow deployment of the airbag. U.S. Pat. No. 5,540,459 assigned to Ford Motor Company describes another arrangement for a side airbag disposed above the door header. In the '459 patent, the airbag deployment forces the headliner inboard so that the airbag can deploy along the lateral side of the vehicle. Although the arrangements that are disclosed in patents '459 and '683 perform satisfactorily, neither includes impact counter measures in their design. The traditional impact countermeasures have been foam and plastic ribs disposed beneath a decorative cover. However, with the addition of these impact counter measures, like ribs of foam, this becomes much more difficult to provide a clear path for airbag deployment. It is therefore desirable to have an airbag system with impact counter measures that allows for deployment of an airbag in a controlled and predetermined direction.